Suspended sediment flux of river: Wavelet analysis in the Panlong basin of the Upper Red River (Honghe River), China

摘要

This paper applied wavelet analysis to examining change tendency, multi-time scale variations, periodic and abrupt change characteristics of suspended sediment flux (SSF) of the Panlong basin in the Upper Red River, China. The results indicated that the SSF had increased from 1951 to 1997, but declined since 1998. The variations of the SSF had multi-time scale characteristics and the fluctuations varied in different time periods. Three periodic time scales, 4, 7 and 22 years, were determined. The 22-year periodic time scale, which was the most obvious one among the three time scales, extended through the whole research period, whereas the 4- and 7-year time scales were obvious only in certain time periods. There were 27 times of abrupt changes across the 4-year time scale, 16 times across the 7-year time scale and 5 times across the 22-year time scale, respectively. On the basis of social statistical and climate data analysis, we concluded that the human activities were the main reason that led to the changing tendency of the SSF, but the characteristics of the multi-time scale, periodic and abrupt change were mainly influenced by climate variations.